Document reading apparatus having a variable designating image

ABSTRACT

A document reading apparatus comprising a document table, a reading section disposed above the document table for reading a document placed on the document table. The reading section includes a sensor for detecting variations of brightness within a selected reading area of the document which is designated by light beams prior to a reading operation. This apparatus further comprises a display device for displaying the image of the selected reading area.

This is a division of prior application Ser. No. 588,651 filed on Sept.26, 1990 for a DOCUMENT READING APPARATUS.

TECHNICAL FIELD

The present invention relates to a reading apparatus for reading anoriginal and providing image information.

BACKGROUND OF THE INVENTION

This type of reading apparatus, generally, employs a mode for reading adocument placed at a predetermined distance, and in particular a modefor reading, from above, a document placed face up. Certain improvementsare desired of such an image reading apparatus. For example, asatisfactory result cannot be obtained if an obstacle enters a spacebetween a document and an image reader for reading the document during areading operation.

To cope with such a situation, some apparatus known in the art read adocument and display its image on a display device. In this case, if anobstacle enters the space between the document and the image reader, theobstacle is displayed along with the document image on the displaydevice. Upon noting the obstacle, the user carries out a readingoperation all over again, However, it is not desirable for the user tohave to watch the display device carefully during a reading operation.

A different problem arises when a reading area is input to the apparatusfor reading only a selected portion of a document. Regarding this areadesignation, there is a type of apparatus which reads a document anddisplays its image on a display device for allowing the user todesignate a desired area on the display device. In another type ofapparatus, a document is placed on a pressure sensitive board for theuser to designate a desired area by pressing the document with a pen orthe like. A further apparatus is known from the Japanese patentapplication laid open under No. 63-232568, in which positions of adocument read are monitored by light beams or spot light during areading operation, and the user turns the scanning operation on and offwhile watching a monitor screen for reading only a desired area of thedocument. It is also possible to designate a desired area of a documentby marking it with a marker pen.

The apparauts that allows the user to designate an area of a document ona display device is complicated and expensive since the display deviceis required. With this type of apparatus, an area cannot be designatedprior to a reading operation. The apparatus including a pressuresensitive board for designating an area on a document surface does notallow the designation on a thick document. The apparatus in which ascanning operation is turned on and off for reading a selected area of adocument is difficult to operate and tends to invite errors. Designationof an area with a marker pen has the disadvantage of marring thedocument.

One of the aspects currently desired is that confirmation is made of anarea of a document to be read when reading the document. To meet thisdemand, certain apparatus have a document table defining a reading rangeof a document, and others indicate a reading range by means of scalesprovided on a document table. A further apparatus is known from theJapanese patent application laid open under No. 62-276958, in which spotor line light is movable with a scanning operation by a reading sensorto illuminate a position of the document currently read.

The apparatus disclosed in the above publication does not show an entirereading range at a time, and is inconvenient for positioning of adocument prior to a reading operation. The other apparatus have thedisadvantage of failing to show clearly which part of a document is readif the document is larger than the document table. The part of adocument is not clearly recognizable even when the document is small.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a document readingapparatus which overcomes the disadvantages of the prior art and meetsthe current demand noted above.

A reading apparatus according to the present invention is constructed toautomatically detect entry of an obstacle into a readable area, that isdetect variations of brightness in that area. This apparatus is capableof efficient reading of a document, and thus positively avoiding errorsin the output of document copies and the like.

Further, with the reading apparatus of the present invention, a desiredreading area of any type of document may be designated reliably throughan easy operation which is carried out by means of light emission.

In addition, the reading apparatus of the present invention can clearlyshow a reading area prior to a reading operation. This feature allowsthe user to confirm the reading area with ease and to effect positionaladjustment as necessary.

In a preferred embodiment of the present invention, a document readingapparatus comprises document reading means for reading a document placedat a predetermined distance therefrom, detecting means for detectingbrightness variations over an area readable by the document readingmeans, and display means for providing a display in response to thedetecting means. According to this construction, during a documentreading operation, a corresponding output is made and brightnessvariations within the reading area are detectable. An alarm is given ifbrightness variations are detected during the reading operation, therebyprecluding errors in copying or printing the document.

The document reading apparatus may further comprise a second detectingmeans for detecting reinstatement of previous brightness following thebrightness variations detected by the first-mentioned detecting means,and canceling means operable in response to the second detecting meansfor canceling the display provided by the display means. According tothis construction, the alarm is automatically stopped upon reinstatementof the previous brightness after the detection of brightness variations.

In a further preferred embodiment of the invention, a document readingapparatus comprises document reading means for reading a document placedat a predetermined distance therefrom, light emitting means for emittinglight for designating an area on the document, and recognizing means forrecognizing the area designated by the light emitted from the lightemitting means.

According to this construction, the detecting means detects the lightemitted from the light emitting means to the desired area of thedocument, the detection result being used by the recognizing means indetermining the location of the desired area. This allows imageinformation corresponding to the designated area to be extracted fromthe image information read by the document reading means.

This apparatus is simple, inexpensive and easy to operate compared withthe apparatus which requires a display device for the user to designatea desired area. Efficiency may be promoted since an area may bedesignated prior to a reading operation. Further, since the area is notdesignated on a pressure sensitive board, the area designation mayeasily be made for a thick document as well. The area designatingoperation is easy and reliable compared with the case of designating anarea while watching a monitor screen during scanning of the document.This apparatus is free from the problem of marring the document as isthe case with designation by means of a marker pen.

In a still further preferred embodiment of the present invention, adocument reading apparatus comprises document reading means for readinga document placed at a predetermined distance therefrom, and lightemitting means for emitting light to an area of the document to be readby the document reading means, the light emitting means having avariable light emitting range.

According to this construction, light may be emitted to the documentsurface prior to a reading operation, to clearly indicate a reading areaof the document. Consequently, the user can confirm the reading arearegardless of the document size, and position the document easily andaccurately for optimal reading results.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescription of preferred embodiments of the invention, as illustrated inthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an outward appearance of an image reading apparatusaccording to the present invention,

FIG. 2 is a perspective view of a reading section,

FIG. 3 is a view illustrating a sensor for recognizing a reading areaand detecting an obstacle,

FIGS. 4 and 5 are explanatory views showing a way in which reading areasof documents are designated, respectively,

FIG. 6 is an explanatory view of light beam framing,

FIGS. 7A, 7B and 7C are flowcharts illustrating a normal copying andprinting operation of the apparatus,

FIG. 8 is a time chart of various flags mentioned in describing theflowcharts,

FIG. 9 is a block diagram showing a construction for extracting areading area,

FIG. 10 is a block diagram of an electric system for emitting lightbeams,

FIG. 11 is a perspective view of a modified construction for detectingan obstacle,

FIG. 12 is a view showing an example of sensors usable in theconstruction shown in FIG. 11,

FIG. 13 is a view showing a light receiving portion of the sensor shownin FIG. 12,

FIG. 14 is a perspective view showing light beam framing in a differentembodiment,

FIG. 15 is a perspective view showing light beam framing in anotherembodiment,

FIG. 16 is a perspective view showing light beam framing in a furtherembodiment, and

FIG. 17 is a schematic view showing a simplified form of the embodimentshown in FIG. 16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A document reading apparatus embodying the present invention will bedescribed hereinafter.

FIG. 1 shows the overall construction of a document reading apparatus.With this apparatus, a document 1 is placed face up on a document table,and a document reading section 2 is mounted in position for reading thedocument 1 from above. The reading section 2 is supported by a supportcolumn 3, with an appropriate distance between the document 1 andreading section 2. This distance is such as to allow visual recognitionof at least a readable area over a document surface at all times, andprovides a working space between the document 1 and reading section 2.The illustrated apparatus further comprises a control unit 2' (includinga CPU 24 and other components to be described later) for controlling adocument reading operation in a predetermined sequence, a light pen 4and operating switches and the like 5.

FIG. 2 shows details of the reading section 2. Image information fromthe document 1 is read by an image sensor 10 through a mirror 14, animaging lens 13 and a mirror 11. The mirror 14 is what is known as amagic or one way transmission mirror which transmits only lighttraveling from one direction (i.e. transmits lights light from a surfacelight source 16 in FIG. 2, which will be described later), and reflectsonly light from the other direction (i.e. reflects light from thedocument 1 in FIG. 2). The mirror 11 is what is known as a cold mirrorwhich transmits only infrared light and reflects visible light. Theimage sensor 10 comprises a semiconductor optical/electrical convertersuch as a CCD, and may be an area sensor or a line sensor. Further, asensor 12 is provided which is sensitive to infrared light forrecognizing a reading area and detecting an object. This sensor 12receives infrared light having passed through the cold mirror 11.Recognition of a reading area means recognition by the document readingapparatus of a selected area of the document when only a portion of thedocument is to be read. Detection of an obstacle means detection of anyobstacle present in the reading area during a document readingoperation. Both functions may be performed by one sensor since thereading area is recognized before the reading operation while theobstacle detection is effected during the reading operation. The sensor12 has a sensitivity range corresponding to an image pickup range of theimage sensor 10.

FIG. 3 shows the construction of the sensor 12. As seen, the sensor 12includes position sensor elements 20 arranged in the direction of x-axisand position sensor elements 21 arranged in the direction of y-axis.Each of these linear infrared sensor elements is electrically insulatedby an insulator such as an infrared transmitting insulating layer notshown. The position sensor elements 20 arranged in the x-direction areconnected to a CPU 24 through a gate circuit 22, while the positionsensor elements 21 arranged in the y-direction are connected to the CPU24 through a gate circuit 23. Sensor output is monitored by the CPU 24.Upon detection of an object by monitoring the sensor output, the CPU 24drives an alarming device 2 such as a buzzer to give an alarm.

The way in which a reading area is recognized by using this sensor 12will be described next.

In FIG. 4, a square EFGH represents a document, and it is assumed that ahatched portion ABCD is a desired reading area. Assume that square ABCDis recognized by designating points A, B, C and D. First, the light pen4 which emits infrared light is used to emit light at a selected pointon the document surface. In FIG. 2, the infrared light is projected tothe sensor 12 through the magic mirror 14, imaging lens 13 and coldmirror 11. As a result, a change occurs to outputs of the x-directionand y-direction sensor elements located at the image point of theinfrared light. This change is detected by the CPU 24 in FIG. 3, wherebyx, y coordinates of the image point are recognized. The reading area maybe recognized by designating the four points in this way. Even a readingarea having a complicated shape as depicted in FIG. 5 may be recoginizedin a similar manner. Since the sensor 12 and image sensor 10 have thecorresponding sensitivity region, data of only a required areas may beobtained by extracting image data from the image sensor 10 based onresults of recognition.

As will be understood from FIG. 3, the area recognizing sensor 12 cannotdetect a position in the x-direction if the image point of the infraredlight is completely confined within one of the y-direction sensorelements 21. To avoid such a situation, the light pen may have asufficiently large light source to project the light onto the sensorelements arranged in the x- and y-directions, or the light may be causedto form a somewhat blurred image point. Where detection is made ofchanges in the outputs of a plurality of sensor elements arranged in thesame direction, the sensor element showing the greatest change may beregarded as representing the image point.

The way in which an obstacle is detected by using the sensor 12 will bedescribed next.

Assume that, in FIG. 2, light beams 18 from unillustrated light sourcesilluminate the document surface. These beams 18 are reflected by thedocument surface and travel through the magic mirror 14 and imaging lens13, and infrared components thereof pass through the cold mirror 11 toimpinge upon the sensor 12. Consequently, any object present in an imagepickup space covered by the image sensor 10 results in a change in theoutput of the sensor 12. The output of the sensor 12 is monitored by theCPU 24 in FIG. 3 for detection of an obstacle. If an obstacle isdetected during a reading operation, the alarming device 25 is drivenimmediately to give an alarm such as by buzzing, and the readingoperation is stopped. Upon removal of the obstacle, the alarm is stoppedand the reading operation is carried out all over again. Where the imagesensor comprises a line sensor, the reading operation may be resumed ata scan position immediately preceding the position at which the objectwas detected.

Further, in FIG. 3, an area for obstacle detection may be varied asdesired by controlling the gate circuits 22 and 23 to select suitable x-and y-direction position sensor elements 20 and 21 for monitoring. Thus,when a reading area is designated, obstacle detection may be effectedonly for this area.

According to this embodiment, brightness variations over the documentsurface may be detected since any variations in the ambient lightemitted to the document are detected.

Light beam framing will be described referring again to FIG. 2. Lightbeam framing means framing of a photographic range or a reading area bymeans of light beams, and is used in positioning the document andconfirming the reading area. In FIG. 2, a uniform surface light source16 is provided which is directed downwardly like backlight in a liquidcrystal television. This light source 16 emits light through a liquidcrystal shutter 17, an imaging lens 15 and the magic mirror 14 to thedocument surface. Preferably, this light has an illuminating rangecorresponding to the image pickup range of the image sensor 10.

FIG. 6 is a view for illustrating the light beam framing. A constructionfor effecting the light beam framing includes an imaging lens 61, aliquid crystal shutter 62, and xy driver 63 and a light source not shown(which is the light source 16 shown in FIG. 2). The liquid crystalshutter 62 is driven by the xy driver 63 for transmitting light throughan unhatched portion. The light from the light source travels throughthe liquid crystal shutter 62 and imaging lens 61 and impinges on asurface of a document 60. The light illuminates an unhatched portion ofthe document 60, thereby setting a frame thereon.

In the above example, the frame is formed by the light beams but lightmay be projected to illuminate the entire area inside the frame. Thelight beam framing is obstructive to the reading operation, andtherefore the light is turned off during the reading operation or onlyduring an integrating operation of the image sensor 10.

FIGS. 7A, 7B and 7C are flowcharts illustrating a normal copying andprinting operation carried out with the document reading apparatusaccording to this embodiment.

When the user turns on an unillustrated power source at step #1, aplurality of flags as shown in Table 1 below are initialized at step #2.

                  TABLE 1                                                         ______________________________________                                        Flags                    ON/OFF                                               ______________________________________                                        Read Flag                OFF                                                  Print Flag               OFF                                                  Page Turn Enable Flag    ON                                                   Copy Area Extract Flag   OFF                                                  Copy Area Designate Enable Flag                                                                        ON                                                   Copy Enable Flag         ON                                                   ______________________________________                                    

After the flags are initialized, checking is made at step #3 whether aswitch for the light beam framing is turned on. If the switched isturned on, the light beams are turned on to illuminate the reading areaat step #4. The user sets a document while looking at the framing atstep #5. If the light beam framing switch is not turned on at step #3,the program jumps to step #5. Next, selection is made at step #6 whetherto copy an entire page or to copy only a portion of the page. If only aportion is to be copied, a copy area is designated at step #7. Theapparatus memorizes this copy area. Step #7 is skipped if the entirepage is to be copied.

Next, the program waits for the copy button to be pressed (step #8).When the copy button is pressed, the page turn enable flag is turned offat step #9. This flag is turned on while the user is selecting a portionto be copied, i.e. preparing for a copying operation, for indicating tothe user that pages should not be turned during the copying operation.

Next, the copy area designated enable flag is turned off at step #10. Asis the page turn enable flag, this flag is turned on while the user ispreparing for a copying operation. Consequently, the user can designatea copy area only when this flag is turned on.

After the copy area designate enable flag is turned off, the copy enableflag is turned off at step #11. As are the two above-mentioned flags,this flag is turned on while the user is preparing for a copyingoperation, for indicating to the user that a coping operation may bestarted.

If the light beams are turned on at step #4, the beams are turned off atstep #12. Then an obstacle detecting operation is started at step #13.After these steps, the read flag is turned on at step #14 for indicatingthat the image reader is in operation, and the reading operation isstarted at step #15. An obstacle detecting operation is carried out atstep #16 during the reading operation. If an obstacle is detected, analarmed is sounded at step #31 (FIG. 7C) and the reading operation isstopped at step #32. Subsequently, the read flag is turned off at step#34.

Meanwhile, at step #35, the sensor 12 is monitored for removal of theobstacle. That is, the sensor output preceding detection of the obstacleis memorized and, when the current sensor output agrees with thememorized output, it is determined that the obstacle has been removed.Upon removal of the obstacle, the alarm is stopped at step #36, the copyenable flag is turned on at step #37, and the program waits for the copybutton to be pressed again at step #38. If the copy buttom is pressed,the program moves to step #11 (FIG. 7A) and repeats the same operationsas noted hereinbefore.

If no obstacle is detected at step #16, or after the obstacle isremoved, step #17 is executed to determine whether the reading operationis completed or not. If the reading operation is completed, the programmoves to the flow shown in FIG. 7B, in which the read flag is turned offat step #18, the obstacle detection is turned off at step #19, the pageturn enable flag is turned on at step #20, and a print flag is turned onat step #21 to indicate that a printing operation is started. Next, step#22 is executed to determine whether a copy area is designated at step#6. If a copy area is designated, the program moves to step #23.Otherwise, the program jumps to step #26. At step #23, the copy areaextract flag is turned on to indicate that the copy area is beingextracted. Then the designated copy area is extracted at step #24. Uponcompletion of the copy area extraction, the copy area extract flag isturned off at step #25. The copy area designate enable flag is turned onat step #26 to indicate to the user that he or she may select a nextcopy area to be read. Then a printing operation is started at step #27.When the printing operation is completed at step #28, the print flag isturned off at step #29, and the copy enable flag is turned on at step#30 to indicate that the apparatus is ready for a next reading (copying)operation. Then the program returns to step #3 in FIG. 7A for repeatingthe described operations.

FIG. 8 is a time chart of the various flags mentioned in describing theforegoing flowcharts. The status of these flags will be described inrelation to a period from a point of time at which the copy button ispressed to a point of time at which the copy button is pressed a secondtime (which corresponds to steps #9 to #30 and steps #3 to #8 in theforegoing flowcharts).

When the copy button is pressed, the read flag is turned on to start areading operation. Simultaneously the page turn enable flag is turnedoff to warn the user that pages should not be turned during the readingoperation. The copy area designate enable flag and copy enable flag arealso turned off to refuse designation of a copy area and operation ofthe copy button. The obstacle detecting operation is also initiated, andthe light beam framing becomes inoperative at the same time.

When the reading operation is completed, the read flag is turned off.The reading operation may be terminated at any time after a CCDintegration (in the case of a line sensor, after an integration at afinal scan position). When the read flag is turned off, the print flagis turned on to start processing and printing image data read. At thesame time, the page turn enable flag is turned on to indicate that pagesmay be turned. The obstacle detecting operation is stopped at this time.If a copy area is designated beforehand, the copy area extract flag isturned on to start extracting the copy area. Then the user confirms thatthe page turn enable flag is turned on, and starts looking for a nextpage to be copied. After the copy area is extracted, the copy areaextract flag is turned off. At the same time, the copy area enable flagis turned on to indicate that designation of a copy area will beaccepted. At this indication, the user designates a copy area if aportion of a certain page is to be copied. Upon completion of theprinting operation, the print flag is turned off. At the same time, thecopy enable flag is turned on to indicate that operation of the copybutton will be accepted. The user must set the document to a properposition before copying. For this purpose, the user turns on the lightbeam framing switch to frame a desired reading area with the lightbeams. The user sets the document by referring to the resulting frame,and then presses the copying button to start copying the desired area.

Status of the page turn enable flag, copy area designate enable flag andcopy enable flag among the various flags mentioned above must be knownto the user, which is indicated by LEDs, buzzers or the like. Status ofthe read flag, print flag and print area extract flag need not benotified to the user, and may be used only as signals for controlpurposes. The copy button and light beam framing switch comprise touchswitches or optical switches which are directly operable by the user.

Constructions for realizing the foregoing reading area extraction andlight beam emission for the light beam framing will be described withreference to simplified block diagrams.

FIG. 9 is a block diagram relating to the reading area extraction. Asystem for extracting a reading area basically includes an image pickupsection 101, a processing section 101, an output section 106, a readingarea recognizing sensor 108, a light pen 109, and a CPU 107 forcontrolling these components. The reading area recognized by the sensor108 is stored in a reading area memory 105 included in the processingsection 100. On the othe hand, image information of the document istransmitted from the image pickup section 101 to a buffer memory 102 tobe accumulated therein. Based on the reading area data stored in thememory 105, an area extractor 103 extracts only necessary informationfrom the image information stored in the buffer memory 102. Theextracted information is transmitted to a memory 104 and output from theoutput section 106. Naturally the sensor 108 may comprise, and it ispreferable that the sensor 108 comprises, the image sensor mentionedhereinbefore.

FIG. 10 is a block diagram relating to the light beam emission. Theillustrated system may share the components of the system describedabove, but different reference numerals are affixed to the componentsshown in FIG. 10 to avoid complication.

Image information of the document is transmitted from an image pickupsection 201 through a processing section 200 to an output section 202 tobe output therefrom. A CPU 204 controls the entire system. In the courseof light beam framing, the CPU 204 receives data of a reading area froma reading area recognizing unit 203, which data is used for causing anxy driver 205 to control a liquid crystal shutter 206 and for turning onand off a light source 207 for the light beam framing.

FIG. 11 shows a modified construction for detecting an obstacle. In FIG.11, numeral 400 denoted a document to be read, numeral 410 an imagesensor, numerals 420 and 440 imaging lenses, numeral 430 a cold mirror,numeral 450 an infrared sensor for detecting an obstacle, and numeral460 light beams from light sources not shown. Image information of thedocument 400 is read by the image sensor 410 through the cold mirror 430and imaging lens 420. Infrared components of the beams 460 reflected bythe document surface are transmitted through the cold mirror 430, andreceived by the infrared sensor 450 through the imaging lens 440. Theinfrared sensor 450 has a light receiving area corresponding to an imagepickup area of the image sensor 410. Consequently, any object present inthe image pickup space results in a change in the output of the sensor450. The object may be detected by detecting this change.

FIG. 12 is a view showing an example of the construction of the infraredsensor 450 shown in FIG. 11. In FIG. 12, numeral 451 denotes a lightreceiver and transducer formed of an infrared conductive material suchas germanium (Ge) or silicon (Si). Numeral 452 denotes ohmic electrodes,numeral 453 a DC source, and numeral 454 a load resistor. Voltages atopposite ends of the resistor 454 vary with variations in the quantityof light incident on the light receiver 451. The CPU 470 detects suchvariations through an analog-to-digital converter 460.

In the above example, if the mirror 430 comprises a half mirror, thesensor 450 may comprise one having sensitivity to visible light. FIG. 13is a view showing a modified obstacle detecting sensor 450A having adifferent shape light receiver which is shown as a hatched portion. Sucha shape results in a reduced size of the light receiver which enables aclear detection of the voltage variations, thereby improving the sensorsensitivity. In the described embodiments, an obstacle is detected bymeans of light beams from ambient light sources. However, this is notlimitative, but the user's hands holding the document and lying on partof the reading area, for example, may also be detected as obstacles. Ineither case, the detection may be made in the form of brightnessvariations.

A simplified construction for the reading area recognition will bedescribed next. In describing this connection, reference is made to FIG.11 since the components shown therein are substantially the same asthose of the construction described below.

In this embodiment of FIG. 11, image information of the document 400 isread by the image sensor 410 through the cold mirror 430 and imaginglens 420. A reading area is recognized by means of infrared light fromthe infrared light pen, which is transmitted through the cold mirror 430and imaging lens 440 to the infrared sensor 450 and converted into asignal. It is to be noted that the output of the sensor 450 is used forthe reading area recognition, whereas the output of the sensor 450described with reference to FIG. 11 is used in monitoring an obstaclepresent in the image pickup space.

The sensor 450 may comprise a visible light sensor if the mirror 430 isa half mirror. Further, the mirror 430 may comprise a movable, ordinarymirror which is movable between a position on an optical path for areading operation as shown in FIG. 11 and a position for allowing thelight beams to reach the sensor 450 during a reading area recognizingoperation.

FIG. 14 shows light beam framing in a different embodiment of thepresent invention. In FIG. 14, numeral 500 denotes a document, numeral510 an imaging lens, numeral 520 a Fresnel lens, numeral 530 a liquidcrystal shutter, and numeral 540 a spot light source. This embodimenthas the same function as the above embodiment, and differs therefrom inthe use of the spot light source 540, and the Fresnel lens 520 forincreasing the brightness of the light beams on the document surface.The Fresnel lens 520 may be disposed between the liquid crystal shutter530 and spot light source 540. Further, the Fresnel lens 520 may bereplaced by a condenser lens.

The light source for the light beam framing may be used for otherpurposes than the light beam framing, such as for illuminating thedocument for reading by the user or by the reading apparatus.

FIG. 15 shows another embodiment, in which numeral 600 denotes adocument, numeral 610 an imaging lens, and numeral 620 a light sourceincluding a plurality of LEDs arranged on a two-dimensional plane. ThisLED light source 620 is driven by an xy driver not shown, so that theLEDs emit light defining corners of a framed area. This embodimentdispenses with the liquid crystal shutter included in the aboveembodiment.

FIG. 16 shows a further embodiment, in which numeral 700 denotes adocument, and numerals 710-740 light sources. Each light source includesa linear light source 750, a cylindrical lens 760 and a cover 770 foremitting light to a surface of the document 700 to effect light beamframing thereon. This embodiment provides light beam framing only forthe image reading range, but its optical system is simplified and doesnot require a shutter element such as a liquid crystal shutter.

FIG. 17 shows a simplified form of the embodiment shown in FIG. 16,which includes four LEDs 820-850 and an imaging lens 810 for forming arectangular reading area on a document 840. This embodiment has asimpler optical system than the embodiment of FIG. 16.

The described light emitting devices for enabling the light beam framingmay be turned on and off by an external operation, and may be turned ononly when necessary. A shutter is not required for a light emittingdevice composed of a plurality of spot light sources arranged on atwo-dimensional plane.

Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to be notedthat various changes and modifications will be apparent to those skilledin the art. Therefore, unless otherwise such changes and modificationsdepart from the scope of the present invention, they should be construedas being included therein.

What is claimed is:
 1. A reading apparatus comprising:reading means forreading an area of an original placed at a predetermined distancetherefrom; and light emitting means for emitting light to the readingarea of said original to be read by said reading means, said lightemitting means providing a variable designating image onto the original,the designating image area matching the reading area.
 2. A readingapparatus as claimed in claim 1, wherein said document reading means ispositioned in front of a surface of said original, which surface holdsinformation being read by the reading means.
 3. A reading apparatus asclaimed in claim 1, wherein said light emitting means includes a liquidcrystal element optically positioned between the original and a lightsource.
 4. A reading apparatus as claimed in claim 1, wherein said lightemitting means includes a light source emitting light reflected from areflecting cover and through a cylindrical lens.
 5. A reading apparatusas claimed in claim 1, wherein said light emitting means includes aplurality of light emitting elements.
 6. An improved reading apparatuscomprising:a support member for supporting an original; a reading meansfor reading an original positioned on the support member, the readingmeans positioned in front of a surface of said original, which surfaceholds information being read by the reading means; and means forprojecting a frame area onto the original, the frame area matching anarea of the original being read by the reading means.
 7. The inventionof claim 6 wherein the frame area is defined by light beams extendingabout the frame area.
 8. The invention of claim 6, wherein the framearea is continuous over the illuminated area.
 9. The invention of claim6 further including means to disable the projecting means during areading cycle.
 10. The invention of claim 6 wherein the means forprojecting a frame area includes a liquid crystal shutter display and alight source emitting light through the shutter display.
 11. Theinvention of claim 6, further including means for designating a readingarea, including a light pens and x and y position sensor elements, thelight pen projecting a light beam that is simultaneously sensed by atleast one x and one y sensor.
 12. The invention of claim 11 furtherincluding means for determining an obstacle exists within the readingarea and providing a corresponding signal.
 13. A method for reading animage of an original, comprising the steps of:projecting a designatingimage having an area onto the original to be read; changing thedesignating image area projected onto the original to match an area ofthe original which is to be read, and reading the area of the originalwhich has been designated by the designating image.
 14. A system forreading a reading area of an original, comprising:a designating image,the designating image having a designating image area projected onto theoriginal, the designating image area being variable so that an operatorcan change the projected designating image area to match the readingarea of the original which is to be read by the system, and means forreading the area of the original defined by the designating image.